dic = { 'name':['一','二'], 'py9':[{'num':71,'avg_age':18}, {'num': 71, 'avg_age': 18}, {'num': 71, 'avg_age': 18} ], True: 1, (1,2,3):'sdlfljsdf', 2:'二哥' } print(dic)
#增加
dic1 = {'age':18,'name':'jin','sex':'male',} dic1['hight'] = 185 #没有就增加 print(dic1) #{'age': 18, 'name': 'jin', 'sex': 'male', 'hight': 185} dic1['age'] = 16 #有就覆盖 print(dic1) #{'age': 16, 'name': 'jin', 'sex': 'male', 'hight': 185} dic1 = {'age':18,'name':'jin','sex':'male',} dic1.setdefault('weight') #没有就增加 print(dic1) #{'age': 18, 'name': 'jin', 'sex': 'male', 'weight': None} dic1 = {'age':18,'name':'jin','sex':'male',} dic1.setdefault('weight',150) #没有就增加 print(dic1) #{'age': 18, 'name': 'jin', 'sex': 'male', 'weight': 150} dic1 = {'age':18,'name':'jin','sex':'male',} dic1.setdefault('name','大一') #有不改变 print(dic1) #{'age': 18, 'name': 'jin', 'sex': 'male'}
#删除
dic1 = {'age':18,'name':'jin','sex':'male',} print(dic1.pop('age')) #有返回值 18,如果没有此键就会报错 print(dic1) #{'name': 'jin', 'sex': 'male'} dic1 = {'age':18,'name':'jin','sex':'male',} print(dic1.pop('二哥',None)) #如果没有此键不报错 print(dic1.pop('二哥','没有此键')) #如果没有此键就显示"没有此键",可油设置返回值 print(dic1) #{'name': 'jin', 'sex': 'male'} dic1 = {'age':18,'name':'jin','sex':'male',} print(dic1.popitem()) #随机删除 返回一个元组('sex', 'male') print(dic1) #{'age': 18, 'name': 'jin'} dic1.clear() #清空字典 del dic1 #删除字典
#更改 更新
#更改 update dic1 = {'age':18,'name':'jin','sex':'male',} dic1['age'] = 16 print(dic1) #{'age': 16, 'name': 'jin', 'sex': 'male'} #更新 dic = {'name':'jin','age':18,'sex':'male'} dic2 = {'name':'alex','weight':75} dic2.update(dic) #在dic2中,有与dic相同的就更新,没有就增加 print(dic2) #{'name': 'jin', 'weight': 75, 'age': 18, 'sex': 'male'}
#查找
dic1 = {'age':18,'name':'jin','sex':'male',} print(dic1.keys(),type(dic1.keys())) #键dict_keys(['age', 'name', 'sex']) <class 'dict_keys'> print(dic1.values()) #值dict_values([18, 'jin', 'male']) print(dic1.items()) #dict_items([('age', 18), ('name', 'jin'), ('sex', 'male')]) for i in dic1: print(i) #打印的键 # age # name # sex for i in dic1.keys(): print(i) #打印的键(同上) for i in dic1.values(): print(i) #打印的值 # 18 # jin # male for i in dic1.items(): print(i) #打印元组 # ('age', 18) # ('name', 'jin') # ('sex', 'male') for i,j in dic1.items(): print(i,j) #打印 # age 18 # name jin # sex male print(dic1['name']) #jin print(dic1.get('name1')) #None print(dic1.get('name1','没有这个键')) #没有这个键
#知识点:
a = 1 b = 2 a,b = b,a print(a,b) #2 1 a,b = [1,2] print(a,b) #1 2 a,b = [1,2],[3,4,5] print(a,b) #[1, 2] [3, 4, 5] a,b = (1,2) print(a,b) #1 2